Does foreign military assistance strengthen or further weaken fragile states facing internal conflict? Aid may strengthen the state by bolstering its repressive capacity vis-à-vis armed non-state actors, or weaken it if resources are diverted to these very groups. We examine how U.S. military...

We use census data for the US, Canada, Spain, and UK to estimate bilateral migration rates to these countries from 25 Latin American and Caribbean nations over the period 1980 to 2005. Latin American migration to the US is responsive to labor supply shocks, as predicted by earlier changes in...

Why do sovereign states sometimes fail to settle territorial disputes peacefully? Also, why do even peaceful settlements of territorial disputes rarely call for the resulting border to be unfortified? This paper explores a class of answers to these questions that is based on the following...

Although most disputes between groups of people are settled peacefully, sometimes disputes result in war. This lecture uses historical examples to illustrate how the ability to negotiate a credible peaceful settlement of a dispute between sovereign states, typically a dispute over the control of...

This paper develops an explanation for historical differences in the ways in which territorial disputes between sovereign states have been resolved. The main innovation in the analysis is to allow for three possible equilibria: ú an unfortified border; ú a fortified but peaceful border; and ú...

Two types of political conflicts of interest pervade many of the world's societies. A horizontal conflict of interest arises when different constituencies support different policies, while a vertical conflict of interest emerges when those in charge of running the government acquire and retain...

In a model of evolution driven by conflict between societies more powerful states have an advantage. When the influence of outsiders is small we show that this results in a tendency to hegemony. In a simple example in which institutions differ in their "exclusiveness" we find that these...

We establish a theoretical as well as empirical framework to assess the role of resource endowments and their geographic location for inter-State conflict. The main predictions of the theory are that conflict tends to be more likely when at least one country has natural resources; when the...

In recent years, cases in which state governments chose to override federal environmental regulation with tighter regulations of their own have become increasingly common, even for pollutants that have substantial spillovers across states. This paper argues that this change arose at least in...

This paper reviews the economics approach to conflict and national borders. The paper provides a summary of ideas and concepts from the economics literature on the size of nations; illustrates them within an analytical framework where populations engage in conflict over borders and resources,...